GPT-6 Luna
Overview
GPT-6 Luna is OpenAI's GPT-6 model for focused, high-volume workloads, released on September 22, 2026. Its model ID is gpt-6-luna. It combines low token prices with adjustable reasoning, image understanding, and a 1,050,000-token context window.
Key Features
- Low-Cost Repeated Tasks: Standard short-context rates support evaluation for high-volume processing.
- Coding Capability: OpenAI reports 66.6% on DeepSWE v1.1 at
maxeffort. - Workflow Efficiency: Designed for repetitive, tool-assisted application workflows where per-run cost matters.
- Adjustable Reasoning: Supports six effort settings, including
none, to adapt computation to task complexity.
Best Use Cases
- Classification and Extraction: Repeated labeling, routing, and structured information extraction.
- Summarization and Rewriting: Processing support records, internal documents, and content drafts at scale.
- Bounded Coding Assistance: Issue triage, test drafting, small fixes, and first-pass reviews.
- Tool-Assisted Routine Work: Repetitive research and application workflows with clearly defined steps.
Capabilities and Limitations
| Capability | Description |
|---|---|
| Reasoning | Supports none, low, medium (default), high, xhigh, and max. |
| Multimodal | Text and image input; text output. |
| Context Window | 1,050,000 tokens. |
| Max Output | 128,000 tokens, including reasoning within the generated-token budget. |
| Tool Use | Responses API supports functions, web and file search, computer use, code interpreter, hosted shell, Apply Patch, MCP, skills, tool search, and image generation. |
| Structured Output | Supports Structured Outputs and streaming. |
| Knowledge Cutoff | May 18, 2026. |
Known Limitations
- Tool calling with reasoning requires the Responses API. Chat Completions supports function calling only at
reasoning_effort: "none". - Reasoning-enabled requests do not support
temperature,top_p, or log-probability controls. Fine-tuning is unsupported. - Requests above 272K input tokens use higher rates for the entire request.
Standard Pricing
The token prices below are shown in USD per 1 million tokens; web search is billed in USD per use.
| Context | Input (USD / 1M Tokens) | 30m Cache Write (USD / 1M Tokens) | 12h Cache Write (USD / 1M Tokens) | Cache Read (USD / 1M Tokens) | Output (USD / 1M Tokens) | Web Search (USD / use) |
|---|---|---|---|---|---|---|
| Up to 272K input tokens | $0.10 | $0.125 | $0.25 | $0.01 | $0.50 | $0.01 |
| More than 272K input tokens | $0.20 | $0.25 | $0.50 | $0.02 | $0.75 | $0.01 |
Credits settlement: B.AI converts charges at 1 USD = 1,000,000 Credits and deducts Credits from the account balance.
- For requests with more than 272K input tokens, the long-context rates apply to the full request.
- Cache-write rates replace the ordinary input charge for those tokens, rather than adding to it. A 30-minute cache write costs 1.25x the applicable input rate; a 12-hour write costs 2.5x. The default minimum lifetime is 30 minutes. Both lifetimes have the same cache-read rate, 0.1x the applicable input rate.
- Web search costs
10,000 Credits($0.01) per use and is not affected by the context tier.
Pricing note
Prices shown in the documentation are B.AI standard reference prices for base billing purposes. B.AI may provide lower actual usage costs through account benefits. Specific prices and account benefits are subject to the platform display and final billing records.